00:00Scientists predict a volcanic eruption likely to be among the most devastating in human history.
00:08The probability that such an event will occur during this century is one in six,
00:13and these repercussions could not only further alter the climate, but also threaten millions of lives.
00:20In January 2022, the Hunga Tonga Hunga Haapai volcano erupted in the South Pacific Ocean,
00:27generating an explosion of considerable magnitude.
00:30This eruption triggered tsunamis that reached the coasts of Japan and America.
00:35The Tonga, on the other hand, suffered damage of such a magnitude
00:38that they represented nearly 20% of the country's gross domestic product.
00:42Researchers at the Niels Bohr Institute in Copenhagen
00:45analyzed ice carcasses taken from Greenland and Antarctica,
00:49and their conclusions are alarming.
00:51A world-scale volcanic disaster could occur.
00:55According to them, the probability of an eruption of an intensity 10 to 100 times higher than that of the Tonga is real.
01:02In the past, cataclysms of this magnitude have profoundly disrupted the climate,
01:07and have even led to the collapse of certain civilizations.
01:10Although the threat of a major volcanic eruption is evident,
01:13specialists believe that the world is not prepared at all.
01:17Michael Cassidy, a volcanologist at the University of Birmingham,
01:21warns against the lack of significant effort to anticipate such a disaster.
01:26He underlines that NASA and other space agencies
01:29are devoting billions of dollars to protection against asteroids,
01:34while a supervolcanic eruption remains a much more likely scenario.
01:38However, to date, no global plan has been developed to face an event of this magnitude,
01:44despite the devastation it could cause.
01:47The last magnitude-7 eruption occurred in 1815 on Mount Tambora, Indonesia.
01:53In the space of a few days, thousands of people lost their lives.
01:57This event also disrupted the climate and caused shortages worldwide,
02:01affecting millions of people.
02:03This is the most powerful eruption ever recorded.
02:06It projected a colossal amount of particles into the atmosphere,
02:10which obscured the sunlight, causing a cooling and plunging the world into chaos.
02:15The following year, the eruption was nicknamed the year without summer.
02:19Temperatures fell, crops were destroyed, famine spread,
02:24and a cholera epidemic killed tens of thousands of people.
02:28A striking detail?
02:29The eruption would have even inspired Mary Shelley to write Frankenstein
02:33when she was forced to stay locked up during this unusually cold summer of 1816 in Switzerland.
02:40Since then, many volcanoes have erupted,
02:43but none equaled Tambora in intensity.
02:46More than two centuries later, scientists warned of a new volcanic threat.
02:51A super-eruption could be imminent, and the world could not be prepared for it.
02:56While researchers seriously evaluate this probability,
02:59experts call for urgent measures before it is too late.
03:04A large-scale volcanic eruption today could prove even more devastating than the year without summer.
03:10Contrary to the time, we are already facing climatic upheavals
03:14and an increased fragility of global systems, which would amplify the consequences.
03:19Dr. Michel Rampinot, a specialist in geology,
03:22warned that the current instability of the world would make a modern mega-eruption even more catastrophic.
03:28Paradoxically, greenhouse gases from fossil fuels
03:31could accentuate post-eruption cooling instead of mitigating it.
03:35In other words, volcanic activity could be a direct threat to humanity.
03:41Dr. Thomas Aubry, a volcanologist,
03:44pointed out that with a warmer and more unstable atmosphere,
03:47sulfur dioxide released by an eruption would spread faster and further than before.
03:52This gas generates sulfate aerosols, which reflect sunlight
03:57and thus contribute to global climate cooling.
04:01These tiny particles, by dispersing more uniformly,
04:05would have a cooling effect even more pronounced than in 1815.
04:09Another Cambridge-based atmosphere specialist
04:11emphasized that their size played a crucial role in the absorption of sunlight.
04:16In a warmer future climate, an eruption could thus accentuate 15% surface cooling.
04:23Many unknowns still exist.
04:25The researchers at the University of Geneva
04:27estimate that we are just beginning to measure the magnitude of the effects of such a phenomenon.
04:31In addition, the estimation of the risks of future eruptions remains difficult,
04:35due to the lack of precise data on ancient volcanic events.
04:39To trace past volcanic activity,
04:41scientists study the ice caps of Greenland and Antarctica,
04:45as well as the cones of ancient trees,
04:48real archives of climatic variations.
04:51These analyses reveal that several eruptions
04:54that occurred over the last millennia
04:56have temporarily cooled the planet from 1 to 1.5 degrees.
05:01One of the most devastating eruptions was that of Samalas in 1257, in Indonesia,
05:07whose power would have triggered the Ice Age,
05:10a period of global cooling that lasted several centuries.
05:13More recently, the eruption of Mount Pinatubo in 1991 in the Philippines
05:18caused a slight terrestrial cooling for a few years.
05:22Thanks to satellites, scientists were able to accurately measure
05:25the amount of sulfur dioxide released and its atmospheric impact.
05:30Despite modern technologies, satellites and seismic instruments,
05:34predicting the next major eruption remains a challenge.
05:37However, even without being able to determine the exact moment,
05:41it is possible to study extreme scenarios
05:43to help authorities anticipate the crisis.
05:46This involves, in particular, the development of evacuation plans
05:49and the formation of food reserves
05:51to deal with the possible loss of crops caused by global cooling.
05:56The alteration of meteorological regimes could increase volcanic activity.
06:01The melting of glaciers eases the pressure exerted on the underground magma,
06:05thus increasing the risk of eruptions.
06:07In addition, the recrudescence of violent precipitation
06:10promotes the infiltration of water into volcanic faults,
06:14which can lead to violent explosions caused by steam.
06:17This phenomenon affects both active volcanoes and those in sleep.
06:21Faced with these dangers,
06:22scientists have established a map of the volcanoes
06:25most prone to climate change.
06:28Their analysis reveals that the most threatening supervolcanoes
06:31are located in Iceland, Chile and Indonesia,
06:35regions where glaciers melt rapidly
06:37or where precipitation increases spectacularly.
06:41A 2022 study identified 716 volcanoes around the world,
06:45i.e. about 58% of known active and emerging volcanoes,
06:49likely to be agitated by extreme precipitation,
06:52which could increase the risk of a new small ice age.
06:56Now let's go back to the eruption of the Hunga Tonga-Hunga Haapai,
07:00which occurred on January 15, 2022.
07:03Scientists have confirmed that it generated the highest volcanic panache
07:06ever recorded.
07:09This underwater volcano in the South Pacific
07:11projected a cinder cloud at an altitude of 57,000 meters,
07:15surpassing all the eruptions previously documented.
07:18What makes this event even more exceptional
07:21is that it is the first volcanic panache to reach the mesosphere,
07:25the third layer of the Earth's atmosphere.
07:28This zone, located at an altitude of 50,000 meters,
07:31is where meteors consume and give birth to shooting stars.
07:36To determine the height of the panache,
07:38researchers at the University of Oxford and RAL Space
07:41used data from three geostationary weather satellites.
07:45Until then, the record was held by the eruption of Mount Pinatubo
07:49in 1991 in the Philippines,
07:51whose panache had culminated at 40,000 meters.
07:54It is interesting to note that this type of measurement
07:57is only possible thanks to recent advances in satellite data,
08:01and that 10 years ago such an analysis would have been impossible.
08:05Another volcano to be closely monitored
08:07due to its destructive potential
08:09is located on the Icelandic peninsula of Reykjanes.
08:12Its last eruption, which occurred in November 2024,
08:16led to the evacuation of the surrounding areas.
08:18Volcanic activity began shortly after 11 p.m.,
08:21without major signs of precursors,
08:23releasing a stream of orange lava
08:25from a 3-kilometer-long crack.
08:27Authorities ordered the evacuation of about 50 houses
08:30as well as the thermal complex of Blue Lagoon,
08:32a tourist destination located southwest of Reykjavik.
08:36Although air traffic has not been disturbed,
08:39authorities have nevertheless warned
08:41about the potentially toxic gas dispersion
08:44in certain areas of the peninsula,
08:46notably on the outskirts of the city of Grindavik.
08:49This locality of 3,800 inhabitants
08:51has been faced with volcanic activity many times
08:54and has undergone eruptions in the past
08:56that damaged its infrastructure
08:58and forced its inhabitants to evacuate.
09:01Thus, in August 2024,
09:03a crack of 3,800 meters
09:05opened at the level of the Sundnukskigar crater,
09:08near Grindavik,
09:09forcing authorities to decree an emergency
09:12while the lava was spreading in several directions.
09:15Fortunately, Icelandic meteorological services
09:18have indicated that this last eruption
09:20was significantly less important
09:22than the one that occurred in August.
09:24Geophysicists performed aerial surveys
09:27and found that the intensity of the event
09:29was less compared to previous eruptions.
09:32For now, Grindavik is not in immediate danger,
09:35but a resumption of activity cannot be ruled out.
09:38Researchers indeed estimate
09:40that new volcanic eruptions are to be foreseen.
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